<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex布局案例1</title>
    <style>
        body,html{
            height: 100%;
        }
        .box{
            background-color: papayawhip;
            height: 100%;
            display: flex;
            flex-direction: column;
        }
        .top,.bottom{
            height: 100px;
            background-color: pink;
        }
        .middle{
            flex: auto;
            display: flex;
            flex-direction: row;
        }
        .middle .left{
            width: 80px;
            background-color: skyblue;
        }
        .middle .right{
            width: 80px;
            background-color: skyblue;
        }
        .center{
            flex: auto;
        }


    </style>
</head>
<body>
    <div class="box">
        <div class="top"></div>
        <div class="middle">
            <div class="left"></div>
            <div class="center"></div>
            <div class="right"></div>
        </div>
        <div class="bottom"></div>

    </div>
    
</body>
</html>